<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Liquid Flow Background</title>
</head>
<style>
  body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: black;
  }

  #liquid-background {
    position: absolute;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, #557C55 40%, transparent 100%);
    animation: liquidFlow 10s linear infinite;
  }

  @keyframes liquidFlow {
    0% {
      transform: translate(0, 0);
    }
    100% {
      transform: translate(-50%, -50%);
    }
  }
</style>
<body>
<div id="liquid-background"></div>
</body>
</html>